1. Field of the Invention
The present invention relates to the field of a wheel axle lifter used for being adapted to be disposed with auto-mobiles.
2. Description of the Prior Art
Speaking of auto mobiles such as trucks and trailers, a body of an auto-mobile is disposed with pairs of wheels to even the loading weight for a reason that the auto-mobile has to transport cargos with huge sizes and heavy weight on roads. However, the auto-mobile needs only two pairs of the wheels for driving on the roads when the auto-mobile loads no cargo. Under this condition of loading no cargo, the auto-mobile such as trucks and trailers would be disposed with a wheel axle lifter to lift up other pairs of the wheels so that the pairs of the wheels lifted would not contact with the ground, decreasing friction between the wheels and the ground and consumption of power needed for overcoming the friction. Thus, a radius on making a U-turn can also be smaller so that a head of the auto-mobile such as trucks or the trailers can make a U-turn easier and with more convenience.
However, the conventional wheel axle lifters would be known by referring to EP0941915. According to this patent, a rubber mat is dispose on a top of an airbag. The rubber mat would abut against a suspending arm and drive the suspending arm to move when the airbag is inflated with or releases air. Because an abutting area where the rubber mat abuts against the suspending arm is smaller, a loading pressure is greater for the rubber mat and the suspending arm. As a result, a steel spring is disposed between the supporting frame and the airbag to stabilize the move of the airbag. In the long term, the use of the steel spring still causes a great possibility of being damaged to the airbag. And the great friction between the rubber mat and the suspending arm also lead the rubber mat and the suspending arm to be damaged easily. Furthermore, as a description of EP1902933, the bearing frame has plural holes used for adjusting a distance between the wheel axle and the body of the auto-mobile. And the lifting device has a bearing used for abutting against the suspending arm. The lifting device drives the bearing to push the suspending arm moving so that the wheel axle moves upwardly or downwardly. Because the abutting area where the bearing abuts against the suspending arm is smaller, a loading pressure is greater for the rubber mat and the suspending arm, and the lifting device would be deformed easily. Under a condition of loading no cargo, the lifting device still maintains a condition of pushing the suspending arm in order to lift the wheel axle for a long time. Apart from being deformed, the lifting device tends to be damaged easily on account of pushing for a long time. And a cost on repairing is increased.
As such, the present invention is arisen to obviate or at least mitigate the above mentioned disadvantages.